Résumé
Objective To study the factors leading to the increased risk of falls when the elderly cross obstacles with different load distributions in their hands, and to explore the gait strategies to prevent falls for elderly people with different load distributions during obstacle crossing. Methods Twelve young healthy (control group) and 12 elderly healthy participants performed walking tasks with or without obstacle crossing at their daily speed under different load distributions. Surface electromyography (sEMG) signals were collected from both sides of the lateral femoris, rectus femoris and medial femoris. Then the average sEMG was analyzed and compared. The numbers of contact incident during obstacle touching were also recorded. Results Age, weight carrying and obstacle all had significant influences on the activity level of lower limb muscles in elderly people. A total of 9 contact incidents occurred in 1 152 obstacle crossing tests. In addition, the contribution of right vastus medialis muscle was the greatest in the elderly and young adults when they completed the weight carrying and obstacle crossing tasks. Conclusions The elderly people had the lowest risk of falling down by taking advantage of the dominant side of the leg to take the lead in obstacle crossing under the uniform distributions of load. The research findings provide references for systematic assessment of fall risk in the elderly and have certain guiding significance for lower limb exercise or rehabilitation training in the elderly.